Portions of this disclosure are described in terms of, e.g., encoded signals for digital designs, product packaging (sometimes just referred to herein as “packaging” or “package”) and other objects. These encoding techniques can be used, e.g., to alter or transform how color inks are printed on various physical substrates. The alterations or transformations preferably result in a printed design carrying machine readable indicia on a surface of a physical object.
Various forms of signal encoding (or “embedding”) include, e.g., “steganographic encoding” and “digital watermarking.” Digital watermarking is a process for transforming physical or electronic media to embed a machine-readable code (or “auxiliary data”) into the media. In some cases the media is transformed such that the embedded code is “obscured” or “generally imperceptible” relative to an overt symbology (e.g., 1D or 2D barcode), yet may be detected through an automated detection process. Obscured and generally imperceptible in this context means that the luminance/chrominance variations in the artwork due to the digital watermarking are not noticeable to a human viewer inspecting the package from a usual distance (e.g., 20 inches) under normal retail lighting (e.g., 50-85 foot candles), who has not previously been alerted to the existence of the digital watermarking.
Digital watermarking is often applied to electronic or physical objects such as printed objects, images, audio signals, and video signals. However, it may also be applied to other types of objects, including, e.g., product packaging, electronics such as circuit boards and CPUs, stickers, logos, product hang tags, line-art, software, multi-dimensional graphics models, and surface textures of such objects.
In this document we use the terms “digital watermark” and “watermark” (and various forms thereof) interchangeably.
Auxiliary data embedding systems typically include two components: an encoder (or embedder) that embeds the auxiliary signal in a host image or object, and a decoder (or detector) that detects and reads the embedded auxiliary signal from the host image or object. The encoder may embed the auxiliary signal by altering or transforming a host image or object to carry the auxiliary data. The detection component analyzes a suspect image, object or signal to detect whether an auxiliary signal is present, and if so, extracts or reads information carried in it.
Several particular digital watermarking and auxiliary data embedding and detection techniques have been developed. The reader is presumed to be familiar with the literature in this field. Particular techniques for embedding and detecting imperceptible digital watermarks are detailed in the assignee's patent documents including US Published Patent Application Nos. 20150156369 and 20160217547; U.S. Pat. Nos. 9,635,378 and 9,819,950; International Application No. PCT/US2015/44904, filed Aug. 12, 2015 (published as WO 2016025631 A1) and U.S. Pat. Nos. 7,054,461, 7,286,685, and 9,129,277. Related technology is detailed in Assignee's U.S. Pat. No. 9,754,341. Each of the patent documents mentioned in this paragraph are hereby incorporated herein by reference in its entirety, including all drawings and any appendices.
One aspect of the disclosure is a printed object comprising: a white substrate or white background comprising a first area; an ink mixture printed at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising extender white and ink including a Phthalocyanine green pigment, the ink mixture comprising a volume or weight ratio of 97.5% to 99.75% white extender and 2.5%-0.25% ink. The first plurality of spatial locations is arranged in a pattern conveying an encoded signal, and the white substrate or white background and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8%-30%. One example of white extender is Pantone® Extender.
Another aspect of the disclosure is a printed object comprising a white substrate or white background comprising a first area; an ink mixture printed at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising extender white and Green 7 ink, the ink mixture comprising a volume or weight ratio of 97.5% to 99.75% white extender and 2.5%-0.25% Green 7 ink. The first plurality of spatial locations is arranged in a pattern conveying an encoded signal, and the white substrate or white background and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8%-30%.
Still another aspect of the disclosure is a printed object comprising: a substrate comprising a first area; a first ink printed within the first area, the first ink comprising a spectral reflectivity of equal to or less any 10% at or around 660 nm; an ink mixture printed over the first ink at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising opaque white ink and Pantone Rubine Red ink, the ink mixture comprising a volume or weight ratio of 68%-76% opaque white ink and 24%-32% Pantone Rubine Red. The first plurality of spatial locations is arranged in a pattern conveying an encoded signal, and the first ink and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8%-30%. For a printed opaque white ink, the term “Pantone” is not typically used in front of “opaque white.”
Another aspect of the disclosure is an image processing method comprising: obtaining optically captured imagery representing a printed object, the imagery captured by a scanner have a peak illumination at or around 660 nm. The printed object comprising: a substrate or background comprising a first area; an ink mixture printed at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising extender white and ink including a Phthalocyanine green pigment, the ink mixture comprising a volume or weight ratio of 97.5% to 99.75% white extender and 2.5%-0.25% ink; in which the first plurality of spatial locations is arranged in a pattern conveying an encoded signal carrying a plural-bit payload, and in which the substrate and background and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8%-30%. The method further includes the acts of processing the captured imagery to decode the plural-bit payload from the encoded signal; and outputting the plural-bit payload.
Further aspects, features, combinations and advantages will become even more apparent with reference to the following detailed description, claims and accompanying drawings.